In 1967, he joined the United States foreign service. At first he worked in Kabul, Afghanistan. He also worked in Blantyre, Malawi from 1968 to 1971. He worked for the United States State Department for 23 years. During that time, he worked for six different Secretaries of State, including Alexander Haig. A Secretary of State is the top government official in the U.S. State Department. A secretary of state is appointed by the United States President. He also worked as a deputy chief at an Americanembassy in the country of Norway. A deputy chief is a person in charge at the embassy.

In 1983, President Ronald Reagan appointed Bremer to the position of Ambassador to the Netherlands. He also became "Ambassador at Large for Counter Terrorism."

Bremer retired in 1989. Then he spent the next 15 years working in private (non-government) companies. One of the companies he worked for was Kissinger Associates (a company that was run by someone who used to be a Secretary of State, Henry Kissinger). He also served as a board member for several corporations. A board member is someone who makes big or strategic decisions on how a company should operate. Mr. Bremer has served on the board for corporations such as Air Products and Chemicals Incorporated, Akzo Nobel NV (a Dutch company), and Marsh Crisis Consulting Company.